Discount calculator
$80 at 25% off is $60, and you save $20. Enter a price and the percent off; add an extra discount or your sales tax rate if you need them.
How the sale price is worked out
- Take the percent offSale price = price × (1 − percent ÷ 100). $80 at 25% off is $80 × 0.75 = $60.
- Apply an extra discount to the sale price"Extra 20% off" comes off the already reduced price, not the original. $60 with an extra 20% off is $60 × 0.8 = $48.
- See the effective discountEffective discount = savings ÷ original price × 100. $32 saved on $80 is 40%, not 45%.
Stacked discounts never simply add up. 30% off and then an extra 20% off is 44% off in total, because the second discount is taken from a smaller price. Two 50% discounts in a row leave you paying 25%, not 0.
Money is rounded to the cent after each step, with half a cent rounding up, the way a price tag would show it. A store that rounds differently can be a cent apart.
Sale prices at common discounts
| Discount | $20 | $50 | $80 | $100 |
|---|---|---|---|---|
| 10% off | $18.00 | $45.00 | $72.00 | $90.00 |
| 15% off | $17.00 | $42.50 | $68.00 | $85.00 |
| 20% off | $16.00 | $40.00 | $64.00 | $80.00 |
| 25% off | $15.00 | $37.50 | $60.00 | $75.00 |
| 30% off | $14.00 | $35.00 | $56.00 | $70.00 |
| 40% off | $12.00 | $30.00 | $48.00 | $60.00 |
| 50% off | $10.00 | $25.00 | $40.00 | $50.00 |
| 70% off | $6.00 | $15.00 | $24.00 | $30.00 |
Worked examples
What is $80 with 25% off?
$80.00 at 25% off is $60.00. You save $20.00.
$80.00 × (1 − 0.25) = $60.00
What is $59.99 with 15% off?
$59.99 at 15% off is $50.99. You save $9.00.
$59.99 × (1 − 0.15) = $50.99
What is $120 at 30% off plus an extra 20% off?
$120.00 at 30% off, then an extra 20% off, is $67.20. You save $52.80, 44% in total.
$120.00 × (1 − 0.3) = $84.00
$84.00 × (1 − 0.2) = $67.20
$52.80 ÷ $120.00 × 100 = 44% effective discountWhat do you pay for $250 at 40% off with 7% sales tax?
$250.00 at 40% off is $150.00. You save $100.00. With 7% sales tax, you pay $160.50.
$250.00 × (1 − 0.4) = $150.00
$150.00 × 0.07 = $10.50 tax
$150.00 + $10.50 = $160.50Is 50% off and then 50% off the same as free?
$100.00 at 50% off, then an extra 50% off, is $25.00. You save $75.00, 75% in total.
$100.00 × (1 − 0.5) = $50.00
$50.00 × (1 − 0.5) = $25.00
$75.00 ÷ $100.00 × 100 = 75% effective discount
Questions
- How do I calculate 25% off?
- Multiply the price by 0.75, because you pay the 75% that is left. $80 at 25% off is $80 × 0.75 = $60. The savings are $80 × 0.25 = $20.
- Is 30% off plus an extra 20% off the same as 50% off?
- No. The extra 20% comes off the sale price, so $120 becomes $84 and then $67.20. That is $52.80 off, or 44% in total, not 50%.
- Does the order of two discounts matter?
- Not for percentages. 30% then 20% and 20% then 30% both leave 56% of the price, because the multiplications can be done in either order. Rounding to the cent between steps can move the result by a cent.
- How do I find the original price from a sale price?
- Divide the sale price by what is left after the discount. A $60 item at 25% off was $60 ÷ 0.75 = $80. The before-a-change calculator does this for any percent.